Vacuum insulation structures with multiple insulators

ABSTRACT

A refrigerator cabinet is provided. The refrigerator cabinet includes an inner liner and an external wrapper. The inner liner is positioned within the external wrapper such that a gap is defined between the external wrapper and inner liner. A first insulator is positioned within the gap, and a second insulator is positioned within the gap. A pressure within the gap is below about 1000 Pa.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of U.S. patent applicationSer. No. 15/776,276 entitled “VACUUM INSULATION STRUCTURES WITH MULTIPLEINSULATORS,” filed May 15, 2018 which is a national stage entry ofPCT/US2016/063966, filed on Nov. 29, 2016, which claims the benefitunder 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No.62/265,055 filed Dec. 9, 2015. The entire disclosures of each areincorporated herein by reference in their entirety.

BACKGROUND

The efficiency of a refrigerator may, at least in part, rely on therefrigerator's ability to keep items within the refrigerator cool andprevent heat from entering the refrigerator. Accordingly, new methodsand materials of insulating a refrigerator are sought.

BRIEF SUMMARY OF THE DISCLOSURE

According to one aspect of the present disclosure, a refrigeratorcabinet is provided. The refrigerator cabinet includes an inner linerand an external wrapper. The inner liner is positioned within theexternal wrapper such that a gap is defined between the external wrapperand inner liner. A first insulator is positioned within the gap, and asecond insulator is positioned within the gap. A pressure within the gapis below about 1000 Pa.

According to another aspect of the present disclosure, a refrigeratorcabinet includes an inner liner and an external wrapper. The inner lineris positioned within the external wrapper such that a gap is definedbetween the external wrapper and internal liner. A first insulator ispositioned within the gap. A second insulator is positioned within thegap. The first and second insulators are segregated.

According to another aspect of the present disclosure, a refrigeratorcabinet includes an inner liner and an external wrapper. The inner lineris positioned within the external wrapper. A first insulator ispositioned proximate a front flange of the cabinet. A second insulatoris positioned proximate the first insulator.

These and other features, advantages, and objects of the presentdisclosure will be further understood and appreciated by those skilledin the art by reference to the following specification, claims, andappended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe disclosure, will be better understood when read in conjunction withthe appended drawings. For the purpose of illustrating the disclosure,there are shown in the drawings, certain embodiment(s). It should beunderstood, however, that the disclosure is not limited to the precisearrangements and instrumentalities shown. Drawings are not necessarilyto scale. Certain features of the disclosure may be exaggerated in scaleor shown in schematic form in the interest of clarity and conciseness.

FIG. 1A is a top perspective view of a refrigerator cabinet, accordingto one embodiment;

FIG. 1B is an exploded top perspective view of the refrigerator cabinetof FIG. 1A, according to one embodiment;

FIG. 1C is a cross-sectional view taken at line IC-IC of FIG. 1A,according to one embodiment;

FIG. 2A is a cross-sectional view taken at line II-11 of FIG. 1A,according to one embodiment;

FIG. 2B is a graph depicting the thermal conductivity of variousinsulator materials as a function of gas pressure;

FIG. 3A is a schematic depiction of a refrigerator cabinet insulatorfilling system, according to one embodiment;

FIG. 3B is a flow chart of a refrigerator cabinet insulator fillingmethod, according to one embodiment;

FIG. 4A is a schematic depiction of a refrigerator cabinet insulatorfilling system, according to one embodiment; and

FIG. 4B is a flow chart of a refrigerator cabinet insulator fillingmethod, according to one embodiment.

DETAILED DESCRIPTION

As required, detailed embodiments of the present disclosure aredisclosed herein.

However, it is to be understood that the disclosed embodiments aremerely exemplary of the disclosure that may be embodied in various andalternative forms. The figures are not necessarily to a detailed designand some schematics may be exaggerated or minimized to show functionoverview. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present disclosure.

As used herein, the term “and/or,” when used in a list of two or moreitems, means that any one of the listed items can be employed by itself,or any combination of two or more of the listed items can be employed.For example, if a composition is described as containing components A,B, and/or C, the composition can contain A alone; B alone; C alone; Aand B in combination; A and C in combination; B and C in combination; orA, B, and C in combination.

It is to be understood that the present disclosure is not limited to theparticular embodiments described below, as variations of the particularembodiments may be made and still fall within the scope of the appendedclaims. It is also to be understood that the terminology employed is forthe purpose of describing particular embodiments, and is not intended tobe limiting. Instead, the scope of the present disclosure will beestablished by the appended claims.

For purposes of description herein, the terms “upper,” “lower,” “right,”“left,” “rear,” “front,” “vertical,” “horizontal,” and derivativesthereof shall relate to the disclosure as oriented in FIG. 1A, unlessstated otherwise. However, it is to be understood that the disclosuremay assume various alternative orientations, except where expresslyspecified to the contrary. It is also to be understood that the specificdevices and processes illustrated in the attached drawings, anddescribed in the following specification, are simply exemplaryembodiments of the inventive concepts defined in the appended claims.Hence, specific dimensions and other physical characteristics relatingto the embodiments disclosed herein are not to be considered aslimiting, unless the claims expressly state otherwise.

Referring to FIGS. 1A-4B, a refrigerator 10 includes a cabinet 14 havingan inner liner 18 and an external wrapper 22. The inner liner 18 ispositioned within the external wrapper 22 such that a gap 26 is definedbetween the external wrapper 22 and internal liner 18. A first insulator30 is positioned within the gap 26 and a second insulator 34 ispositioned within the gap 26. A pressure within the gap 26 may be belowabout 1000 Pa.

Referring now to FIGS. 1A and 1B, the refrigerator 10 includes thecabinet 14. The refrigerator 10 may take a variety of configurationsincluding French door, side-by-side, top freezer, bottom freezer,counter depth, compact, built-in, and other types of refrigerators. Thecabinet 14 includes the inner liner 18, the external wrapper 22 and mayoptionally include a shell 42. In the depicted embodiment, the innerliner 18 has a generally rectangular box shape, but may take a varietyof shapes including a cube, prism, parallelepiped, etc. and combinationsthereof. The inner liner 18 may have a liner flange 46 disposed aroundthe inner liner 18 and connected to a plurality of liner walls 50 whichdefine the inner liner 18. The inner liner 18 may be formed from apolymeric material having high barrier properties (e.g., low gaspermeation), metals and combinations thereof. The inner liner 18 may beformed via thermoforming, injection molding, bending and/or forming. Theliner walls 50 of the inner liner 18 may have a thickness ranging frombetween about 0.1 mm to about 3.0 mm. In a specific embodiment, theliner walls 50 have a thickness of about 0.5 mm.

The inner liner 18 is shaped and configured to mate, couple or otherwisebe positioned within the external wrapper 22. The external wrapper 22includes a plurality of wrapper walls 58 to which a wrapper flange 62 iscoupled. The wrapper flange 62 and the liner flange 46 are configured tobe coupled when the cabinet 14 is in an assembled configuration. Thecoupling of the liner flange 46 and the wrapper flange 62 may beperformed such that an airtight, or hermetic, seal is formed between theinner liner 18 and the external wrapper 22. The hermetic seal of thewrapper flange 62 and the liner flange 46 may be achieved through use ofadhesives, welding, an elastomeric gasket under compression and/orcrimping. The coupling of the liner flange 46 to the wrapper flange 62may be performed proximate a front flange area 64 (FIG. 2A) of thecabinet 14. The front flange area 64 may be configured to couple with adoor which permits access to an interior of the cabinet 14.

The external wrapper 22 may be formed of and by any of the materials andprocesses listed above in connection with the inner liner 18. Thewrapper walls 58 of the external wrapper 22 may have a thickness rangingfrom between about 0.1 mm to about 3.0 mm. In a specific embodiment, thewrapper walls 58 have a thickness of about 0.5 mm. The wrapper walls 58of the external wrapper 22 may define an injection port 66 and/or avacuum port 70. The external wrapper 22 may include one or multipleinjection ports 66 and/or vacuum ports 70. The injection ports 66 and/orvacuum ports 70 may be positioned as illustrated or in a variety ofpositions about the external wrapper 22. It will be understood that inalternative embodiments, the injection ports 66 and/or vacuum ports 70may be disposed on both the external wrapper 22 and inner liner 18, orsolely on the inner liner 18. The injection port 66 and the vacuum port70 may be used to access (e.g., to inject an insulator, draw a vacuumand/or perform maintenance within) the gap 26 once the inner liner 18and the external wrapper 22 are bonded. The injection port 66 and thevacuum port 70 may have a diameter of between about 10 mm and about 50mm, or between about 12.5 mm and about 25 mm. In various embodiments,the injection port 66 and the vacuum port 70 may have differentdiameters than one another. Similarly, in embodiments utilizing morethan one injection port 66 and vacuum port 70, the sizes of theinjection ports 66 and the vacuum ports 70 may vary.

Referring now to FIG. 1C, the inner liner 18 and the external wrapper 22may be joined via a trim breaker 72. The trim breaker 72 may be formedof a plastic, a metal, a composite and/or insulating materials. The trimbreaker 72 may define a liner joint 72A configured to couple the innerliner 18 to the trim breaker 72. The trim breaker 72 may also define awrapper joint 72B configured to couple the external wrapper 22 to thetrim breaker 72. The liner joint 72A and the wrapper joint 72B may bevibration welded, crimped, thermally bonded, adhesively bonded orotherwise coupled to render the gap 26 airtight. The trim breaker 72 maybe used to hold the inner liner 18 and the external wrapper 22 togetherand in place. Use of the trim breaker 72 may provide advantages ofresisting thermal bridging between the inner liner 18 and the externalwrapper 22 and easing manufacturing.

Referring now to FIG. 2A, once the inner liner 18 and the externalwrapper 22 have been joined and the gap 26 defined, the first insulator30 and the second insulator 34 may be dispensed into the gap 26. The gap26 may have a thickness of between about 12 mm to about 30 mm. The gap26 may have an air pressure of less than about 1 atm (101,325 Pa,1013.25 mbar), less than about 0.5 atm (50,662.5 Pa, 506.63 mbar), lessthan about 0.1 atm (10,132.5 Pa, 101.33 mbar), less than about 0.001 atm(101.325 Pa, 1.0133 mbar) or less than about 0.00001 atm (1.01 Pa, 0.01mbar). Over the service life of the refrigerator 10 (FIG. 1A), the airpressure within the gap 26 may rise more than about 0.001 atm (101 Pa,1.01 mbar), greater than about 0.005 atm (506 Pa, 5.06 mbar) or greaterthan about 0.01 atm (1,013 Pa, 10.13 mbar) due to diffusion and/orpermeation of gases into the gap 26 through the inner liner 18 and/orthe external wrapper 22. The first and second insulators 30, 34 may be amaterial configured to have low thermal conductivity. For example, thefirst and second insulators 30, 34 may include precipitated silica,polyurethane foam, fumed silica, silica fume, beads (e.g., of glass,ceramic, and/or an insulative polymer), hollow organic micro/nanospheres, hollow inorganic micro/nano spheres, silica aerogel,nano-aerogel powder, rice husk ash, diatomaceous earth, cenospheres,perlite, glass fibers, polyisocyanurate, urea foam, rice hulls,polyethylene foam, vermiculite, fiberglass and combinations thereof.Optionally, an opacifier (e.g., TiO₂, SiC and/or carbon black) may beincluded in the first and/or second insulators 30, 34. Additionally oralternatively, materials configured to change the radiation conduction,flow properties and packing factor of the first and second insulators30, 34 may be introduced. Further, one or more gas (e.g., oxygen,hydrogen, carbon dioxide) and/or moisture getters may be included in thefirst and second insulators 30, 34. The first and second insulators 30,34 may include the same insulating material as one another, may besubstantially the same material, or may be completely differentmaterials.

In embodiments where the first and/or second insulators 30, 34 includeorganic spheres, the organic spheres may include polystyrene,polythiophenes, polyethylene, rubber and/or combinations thereof. Inembodiments where the first and/or second insulators 30, 34 includeinorganic spheres, the spheres may include glasses, ceramics andcombinations thereof. In embodiments where the first and/or secondinsulators 30, 34 include beads or spheres, the beads or spheres mayhave an average outer diameter ranging from about 50 nm to about 300μ,or from about 1μ to about 300μ, or from about 50 nm to about 1000 nm. Invarious embodiments, the diameter size distribution of the spheres islow. Sphere embodiments of the first and/or second insulators 30, 34 maybe filled with a single gas (e.g., H₂, O₂, N₂, noble gases, volatileorganic compounds, CO₂, SO, SO₂) or a mixture of gases (e.g.,atmosphere, noble gases, O₂, SO₂, SO). The spheres may be sealed andhave a gas pressure within the spheres of between about 0.1 atm andabout 1.0 atm, or between about 0.2 atm and about 0.5 atm, or betweenabout 0.25 atm and about 0.35 atm. The first and/or second insulators30, 34 are positioned within the gap 26 and in contact with both thewrapper walls 58 and the liner walls 50. The packing factor of the firstand/or second insulators 30, 34 within the gap 26 may be greater thanabout 60%, greater than about 62%, greater than about 65%, or greaterthan about 70%.

In embodiments where the first and/or second insulators 30, 34 includefumed silica, the fumed silica may be hydrophobic and/or hydrophilic.The fumed silica may have a particle size ranging from less than about0.005μ to greater than about 1.0μ. The fumed silica may have a densityof between about 32 kg/m³ to about 80 kg/m³. When positioned within thegap 26, the fumed silica may have a density between about 50 kg/m³ toabout 300 kg/m³, or between about 80 kg/m³ to about 250 kg/m³ or betweenabout 150 kg/m³ to about 200 kg/m³.

The first and second insulators 30, 34 are configured not only tothermally insulate the inner liner 18 from the external wrapper 22, butalso to resist the inward directed force of the atmosphere on the lowerthan atmosphere pressure of the gap 26. Atmospheric pressure on theinner liner 18 and the external wrapper 22 may cause distortions whichare unsightly and may lead to a rupture in either of the inner liner 18or the external wrapper 22 thereby causing a loss of vacuum in the gap26. Further, drawing the vacuum in the gap 26 may cause an impact orshock loading of the first and second insulators 30, 34 as the innerliner 18 and the external wrapper 22 contract around the first andsecond insulators 30, 34. Accordingly, the first and second insulators30, 34 should have sufficient crush resistance to resist deformation ofthe inner liner 18 and the external wrapper 22 due to a pressuregradient between the atmosphere and an air pressure of the gap 26.

The first insulator 30 may be positioned within, and proximate to, thefront flange area 64 of the cabinet 14 and the second insulator 34 mayfill the rest of the gap 26. In the depicted embodiment, a filter 74 ispositioned between the first insulator 30 and the second insulator 34.The filter 74 may be made of paper, a polymeric material, a ceramicand/or a metal. The filter 74 may be porous, solid and/or coupled to theinner liner 18 and/or the external wrapper 22. Use of the filter 74 mayresist or prevent the migration and mixing of the first and secondinsulators 30, 34 such that the first and second insulators 30, 34remain segregated. The front flange area 64, due to its thinner crosssection and being surrounded by atmosphere on three sides, may sufferfrom a thermal, or heat, bridging effect. Such a thermal bridging acrossthe front flange area 64 may result in an overall reduced efficiency ofthe refrigerator 10. Accordingly, in various embodiments the firstinsulator 30 may have a higher insulating property than the secondinsulator 34. In such an embodiment, the higher insulating property ofthe first insulator 30 may be sufficient to reduce, or eliminate anythermal bridging taking place through the front flange area 64.

Referring now to FIGS. 2A and 2B, as explained above, the gap 26 withinthe cabinet 14 may undergo a pressure increase over the service life ofthe refrigerator 10 due to permeation and/or diffusion of gases. Assuch, selection of the first and second insulators 30, 34 may accountfor the expected change in pressure within the gap 26. As can be seen inFIG. 2B, fumed silica undergoes the smallest increase in thermalconductivity over an expected pressure change range (e.g., between about1 mbar and about 10 mbar), followed by precipitated silica. As such, useof fumed silica as the first insulator 30 and precipitated silica and/orcombinations of insulators (e.g., precipitated silica and spheres) asthe second insulator 34 may not only reduce thermal bridging across thefront flange area 64 while the gap 26 is at manufactured pressure, butalso over the service life of the refrigerator 10.

Referring now to FIGS. 3A and 3B, one embodiment of a first method 80 ofinserting the first and second insulators 30, 34 within the gap 26 isdepicted. The first method 80 includes step 84, step 88, step 92, step94 and step 96. In step 84, the inner liner 18 is positioned within theexternal wrapper 22 as explained in greater detail above. The linerflange 46 and the wrapper flange 62 may be bonded so as to make the gap26 airtight. Next, step 88 of drawing a vacuum may be performed. Avacuum, or negative pressure relative to atmospheric pressure, isgenerated within the gap 26. The vacuum is created by drawing the airout of the gap 26 through the at least one vacuum port 70. A pump orother suitable vacuum sources may be connected to the vacuum port 70 tofacilitate drawing the vacuum. Additionally or alternatively, the firstmethod 80, or any of its steps, may be performed within a vacuum chamber98 to provide the vacuum to the gap 26.

Next, step 92 of injecting the first insulator 30 into the gap 26 isperformed. Injection of the first insulator 30 into the gap 26 may beaccomplished by feeding the first insulator 30 into a hopper 100 whichin turn supplies the first insulator 30 to a transfer mechanism 104. Thetransfer mechanism 104 may be a powder pump, a vacuum transfer device,pneumatic pump, flexible screw conveyor, auger feeder and/or otherdevices capable of transferring or moving the first and secondinsulators 30, 34. The transfer mechanism 104 pumps or otherwise injectsthe first insulator 30 into the gap 26 of the cabinet 14 (FIG. 1A). Thetransfer mechanism 104 may utilize fluidization of the first insulator30 to move the first insulator 30 into the gap 26. The transfermechanism 104 may dispense the first insulator 30 into the cabinet 14with or without pressure. Use of the transfer mechanism 104 allows thefirst insulator 30 to be inserted into the gap 26 without anydensification or compaction, while also providing an easy and efficientmeans of inserting the first insulator 30. Once the first insulator 30has sufficiently filled the front flange area 64 of the cabinet 14 andoptionally been leveled off, the filter 74 may be placed on top of thefirst insulator 30 and optionally coupled to the inner liner 18 andexternal wrapper 22. Next, step 94 of injecting the second insulator 34is performed. Injection of the second insulator 34 may be performed insubstantially the same manner as injection of the first insulator 30 iscarried out in step 92. In other embodiments, the second insulator 34may be dispensed or injected under different conditions that produce adifferent packing factor or density of the second insulator 34 relativeto the first insulator 30.

Next, step 96 of vibrating at least one of the inner liner 18 and theexternal wrapper 22 is performed. Vibration of the inner liner 18 and/orthe external wrapper 22 may cause the first insulator 30 to increase itspacking factor. During steps 84, 88, 92, 94 and/or 96 the inner liner 18and/or external wrapper 22 may be supported by one or more supports 106such that relative motion between the inner liner 18 and the externalwrapper 22 is minimized or prevented. The supports 106 may allow thethickness of the gap 26 to remain constant through filling andvibration. It will be understood that although method 80 was describedin a specific order, the steps may be performed in any order orsimultaneously without departing from the spirit of this disclosure.

Referring now to FIGS. 4A and 4B, depicted is a second method 108 ofdispensing the insulator 30 within the gap 26 between the inner liner 18and the external wrapper 22. The second method 108 includes step 112,step 116, step 118, step 120 and step 124. The second method 108 beginswith step 112 of positioning the inner liner 18 within the externalwrapper 22 and sealing the gap 26, as disclosed above. Next step 116 ofdispensing the first insulator 30 within the gap 26 is performed. In thesecond method 108, dispensing of the first insulator 30 into the gap 26may be accomplished through a back aperture 132. The back aperture 132may take a variety of shapes (e.g., square, rectangular, circular,oblong, and combinations thereof) and sizes which are configured toallow the first insulator 30 to be poured or otherwise dispensed intothe gap 26. The first insulator 30 may be dispensed into the gap 26between the inner liner 18 and the external wrapper 22 via the transfermechanism 104 (FIG. 3A), pouring the first insulator 30, or manualapplication. In embodiments of the cabinet 14 (FIG. 1A) where theexternal wrapper 22 includes the back aperture 132, the external wrapper22 may not include the injection port 66 (FIG. 3A). Optionally, step 116may be performed while at least one of the inner liner 18 and theexternal wrapper 22 are vibrated. Vibration of the inner liner 18 and/orthe external wrapper 22 may facilitate in shaking or vibrating the firstinsulator 30 into its maximum packing factor and facilitate a morecomplete filling of the gap 26. Optionally, once the front flange area64 is sufficiently filled with the first insulator 30 and optionally thefirst insulator 30 has been leveled off, the filter 74 may be placed onthe first insulator 30 as described above.

Once the front flange area 64 of the gap 26 between the inner liner 18and the external wrapper 22 is filled with the insulator 30 andsufficiently packed with the first insulator 30, step 118 of dispensingthe second insulator 34 is performed. Dispensing of the second insulator34 may be accomplished in a substantially similar manner to thatdescribed in connection with the first insulator 30 in step 116. Next,step 120 of positioning a back plate 142 over the back aperture 132 isperformed. The back plate 142 may be constructed of the same or similarmaterial as the external wrapper 22, or a different material. Once theback plate 142 is positioned over the back aperture 132, the back plate142 is sealed to the external wrapper 22 to form an airtight, orhermetic, seal. After step 120 is completed, step 124 of drawing avacuum within the gap 26 is performed. The vacuum may be drawn throughthe vacuum port 70 (FIG. 3A) of the external wrapper 22. Additionally oralternatively, method 108, or individual steps thereof, may be performedwithin the vacuum chamber 98 such that drawing a vacuum may not benecessary, or less vacuum can be drawn. Further, the second method 108may utilize the supports 106 to resist relative motion of the innerliner 18 and the external wrapper 22. It will be understood that stepsof the first and second methods 80, 108 may be omitted, combined, mixedand matched, or otherwise reordered without departing from the spirit ofthis disclosure.

Use of the present disclosure may offer several advantages. For example,use of the present disclosure allows for the formation of vacuuminsulated cabinets 14, panels, and structures without noticeabledeformation of the inner liner 18 and the external wrapper 22. Byfilling the gap 26, deformation of the inner liner 18 and the externalwrapper 22 from the pressure differential between the atmosphere and thegap 26 is resisted by the first and second insulators 30, 34. Vacuuminsulated cabinets 14, panels and structures may provide enhancedinsulative properties as compared to traditional foam filled insulatingstructures in addition to a reduced size (e.g., thickness decrease ofgreater than about 55%, 60% or 70%). Additionally, use of the disclosuremay allow for the construction of a less dense cabinet 14 while alsoproviding increased rigidity due to the use of the first and secondinsulators 30, 34. Further strategic use of the first insulator 30 inmore critical insulation areas (e.g., in the front flange area 64, incorners and/or thin locations) and the second insulator 34 in the restof the cabinet 14 may allow for a cost savings in embodiments where thefirst insulator 30 is more expensive (e.g., fumed silica) than thesecond insulator 34 (e.g., precipitated silica). Even further, inembodiments where the first insulator 30 has a lower increase in thermalconductivity per unit pressure increase than the second insulator 34,use of the first insulator 30 proximate the front flange area 64 allowsfor a greater resistance to thermal bridging as the pressure within thegap 26 increases over the service life of the refrigerator 10. It willbe understood that although the disclosure was described in terms of arefrigerator, the disclosure may equally be applied to coolers, ovens,dishwashers, laundry applications, water heaters, household insulationsystems, ductwork, piping insulation, acoustical insulation and otherthermal and acoustical insulation applications.

In this specification and the appended claims, the singular forms “a,”“an” and “the” include plural reference unless the context clearlydictates otherwise. For the purposes of describing and defining thepresent teachings, it is noted that the terms “substantially” and“approximately” are utilized herein to represent the inherent degree ofuncertainty that may be attributed to any quantitative comparison,value, measurement, or other representation. The terms “substantially”and “approximately” are also utilized herein to represent the degree bywhich a quantitative representation may vary from a stated referencewithout resulting in a change in the basic function of the subjectmatter at issue.

It is to be understood that variations and modifications can be made onthe aforementioned structure without departing from the concepts of thepresent disclosure, and further it is to be understood that suchconcepts are intended to be covered by the following claims unless theseclaims by their language expressly state otherwise.

What is claimed is:
 1. A cabinet for a refrigerator, comprising: awrapper; a liner disposed within the wrapper and defining a gap betweenthe liner and the wrapper; a trim breaker coupled to the wrapper and theliner; a first insulator disposed within the gap; a second insulatordisposed within the gap and segregated from the first insulator; and afilter disposed within the gap and positioned between the firstinsulator and the second insulator.
 2. The cabinet of claim 1, whereinthe filter is coupled to the wrapper and the liner.
 3. The cabinet ofclaim 1, wherein the filter comprises a ceramic material configured tominimize mixing of the first insulator and the second insulator.
 4. Thecabinet of claim 1, wherein the first insulator includes glass fibers.5. The cabinet of claim 1, wherein the second insulator includesinorganic spheres.
 6. A method for manufacturing a vacuum insulatedstructure, comprising: positioning an inner liner within an externalwrapper and defining a gap between the inner liner and the externalwrapper; drawing a vacuum to seal the gap; injecting a first insulatorinto the gap; positioning a filter proximate to the first insulatorwithin the gap; and injecting a second insulator into the gap proximateto the filter.
 7. The method of claim 6, further comprising the step of:vibrating at least one of the inner liner and the external wrapper. 8.The method of claim 7, further comprising the step of: using supports tomaintain a thickness of the gap during the vibration of at least one ofthe inner liner and the external wrapper.
 9. The method of claim 6,wherein the step of positioning a filter proximate to the firstinsulator further comprises the step of: coupling the filter to theinner liner and the external wrapper.
 10. The method of claim 6, whereinthe step of injecting a first insulator into the gap further comprisesthe step of: dispensing the first insulator into the gap via a transfermechanism.
 11. The method of claim 9, further comprising the step of:utilizing fluidization of the first insulator to dispense to the firstinsulator with the transfer mechanism.
 12. The method of claim 6,further comprising the step of: leveling the first insulator within thegap.
 13. The method of claim 6, wherein the step of injecting a firstinsulator further comprises the step of: injecting the first insulatorproximate to a front flange area defined by the inner liner and theexternal wrapper.
 14. A method for manufacturing a cabinet for arefrigerator, comprising: positioning a liner within a wrapper to definea gap; dispensing a first insulator within the gap through a backaperture of the wrapper; positioning a filter on the first insulator;and dispensing a second insulator within the gap through the backaperture and proximate to the filter.
 15. The method of claim 14,further comprising the step of: bracing the liner and the wrapper withsupports.
 16. The method of claim 14, further comprising the steps of:vibrating the liner and the wrapper; and leveling the first insulatorwithin the gap.
 17. The method of claim 14, further comprising the stepof: positioning the liner and the wrapper within a vacuum chamber todefine a vacuum in the gap.
 18. The method of claim 14, furthercomprising the step of: coupling a back plate to the wrapper to define ahermetic seal.
 19. The method of claim 18, further comprising the stepof: drawing a vacuum via a vacuum port defined by the wrapper.
 20. Themethod of claim 14, wherein the step of dispensing the first insulatorfurther comprises the step of: dispensing the first insulator proximateto a front flange area defined by the wrapper and the liner.